Photographic camera



Sept. 1, 1959 P. FAHLENBERG PHOTOGRAPHIC CAMERA Filed Sept. 14, 1956 2Sheets-Sheet 1 Sept. 1, 1959 P. FAHLENBERG PHOTOGRAPHIC CAMERA Filedsept. 14, 195e 2 Sheets-Sheet 2 United States Patent PHOTOGRAPHIC CAMERAPaul Fahlenberg, Baierbrunn, `near Munich, Germany, assignor to HansDeckel, Munich, Germany, and Friedrich Wilhelm Deckel, Zug, SwitzerlandThe present invention relates to a photographic camera and in particularto a camera incorporating a depth of ield indicator with movablepointers actuated by the aperture setting mechanism.

Cameras are already known in which the limits of satisfactory definitionobtained with any stop aperture are automatically indicated on thefocusing scale. Generally when a picturepis taken, little attention ispaid to this indication and, to an average distance, more particularlywhen the aperture is fairly small, and the depth of fieldcorrespondingly large, part of the available depth of field extendsbeyond lthe infinity point and is not therefore utilized. In fact, whenthe lens is focused to infinity, half the total available depth of thefield is entirely lost.

It is the object of the present invention to avoid this loss. Theinvention which relates to cameras with an automatic depth of fieldindicator consists in that the member which carries the focusing scaleis provided with means (stops, notches, or the like) which cooperatewith at least one of the pointers of the depth of eld indicator andlimit the possible range of relative adjustment of focused distance andstop aperture. in an advantageous form of construction the arrangementis such that at least one of the pointers of the depth of fieldindicator can be connected with the member that carries the focusingscale for the purpose of effecting a joint adjustment of focuseddistance and stop aperture.A

Several illustrative embodiments of the invention will be hereinafterdescribed with reference to the drawings, in which:

Fig. 1 is a diagramof a photographic camera shown in plan;

Figs. 1A and 1B are sectional and front views, respectively, of adetailthereof;

Fig. 2 and Fig. 2A show an embodiment of the invention in the case of acamera with a coupled range nder;

Fig. 3 is a third embodiment of the invention;

Fig. 4 isa modification of the embodiment shown by Fig. 1; and

Fig. 5 is a diagrammatic perspective view of the principal operatingparts of a depth of field indicator which is suitable for use inconnection with the present invention.

Figure l shows a photographic camera with a camera tbody 1, to the faceof which is secured a lens 2 and a shutter 3. For setting the shutterspeed and the stop there are provided a shutter speed ring 4 and anaperture setting ring 5, the selected speed and stop aperture beingindicated at 6 and 7. For focusing the camera there is-urther provided arotatable focusing ring 8 which carries the focusing scale 9 andregisters with the stationary central index mark 10. The lens and theshutter are longitudinally displaced `in the conventional manner forinstance by means of a thread. For the automatic indication of the depthof the eld the camera carries two pointers 11 and 12 which are adaptedto register with the focusing scale 9. These two movable pointers areactuated by the stop setting ring 5 through an appropriate gearing whichcauses the angular distance between the two pointers to be automaticallycontrolled by the stop setting ring in such a way that the two pointers11 and 12 indicate the limits of satisfactory denition on the focusingscale. There are various possible ways of relatively disposing thefocusing scale, the focusing ring, the index mark and the depth of eldindicator and these have been described by U.S. patent applications Ser.No. 555,964, led December 28, 1955; Ser. No. 557,183, filed January 3,1956; Ser. No. 558,375, filed January 10, 1956.

So far as the present invention is concerned, the mechanism foroperating the depth of eld indicators in all three of the copendingapplications just mentioned is essentially the same, and any one ofthese mechanisms may be used for purposes of the present invention. Fig.5 of the present drawings is essentially a duplicate of Fig. l of thedrawings of the above mentioned application No. 555,964, except forchange of reference numerals, and the construction shown in this Fig. 5is suitable for use in connection with the present invention. Suchconstruction may be briefly described as follows:

The construction includes, within the shutter, two axially spacedstationary rings or annular plates and 150, and two rotary rings 116 and118 axially spaced from each other, between the rings 120 and 150. Theserings are all concentric relative to the optical axis.

The ring 116 carries a radially extending arm terminating in the depthof eld pointer or indicating member 11, and the ring 118 carries aradially extending arm terminating in the depth of field pointer orindieating member 12. The two rings 116 and 118 are coupled to eachother to move through equal amounts in opposite directions. Thepreferred coupling comprises two pinions 122 and 124 rotating on theirrespective stub shafts 123 and 125 xed to the stationary plate 120 andextending in directions parallel to the optical axis. The pinion 122meshes with gear teeth 126 formed on a portion of the periphery of theiirst ring 116, and also meshes with teeth of the other pinion 124which, in turn, meshes also with gear teeth 128 formed on a portion ofthe periphery of the second ring 118. The two pinions are of equal size,so that when either ring moves in one direction, the other ring willmove to an equal angular extent in the opposite direction.

For operating these rings 116 and 118 so as to move the pointers 11 and12 over the focus distance scale 9, there is a ring 130 also mounted forrotation concentrically with the optical axis, this ring having an arm132 which enters a notch in the diaphragm aperture adjusting member orstop adjusting member 5, so that whenever the diaphragm is adjusted to adifferent aperture, the turning of the member 5 will cause correspondingturning of the ring 130, 132. The rotary movements of the part 130,resulting from changes in the diaphragm aperture or stop, aretransmitted to the rings 11-6 and 118 through transmission means sodesigned that the pointer rings 116 and 118 may, if necessary, be movedin a non-linear relation to the movements of the ring 30, to any extentof irregularity or disconformity required by the particular depth ofiield characteristics of the lens system employed or by the particulararrangement of the graduations of the focusing scale or distance scale 9relative to the graduations of the diaphragm aperture scale 7. Toaccomplish this, a stub shaft 136 is carried by and xed to the ring 130,and extends parallel to the optical axis, and has a reduced forward end138 on which is rotatably mounted the plate 40 lying in a plane betweenthe rings 116 and 118. At one point the plate 140 carries a forwardlyprojecting pin 142 which extends into and is movable along l aslot,144formed inzthe :ring-116. :Atranotherapoint `on the plate 140 is` a4controlI pin 1146..which-projects forwardly through a controllingguideslotor cam slot 1 i148 in the fixed ring-150. The pins .1142and-'146 are any `extent necessary, l as -theplate moves'bodilyVv in:one

direction or the other along With'thefring'ff130,when the 1 diaphragmaperture isfchanged.. 4Thefshape of the cam slot 148 is, of coursedesigned'to givefthewdesired-motion to the plate 140,y dependingupon-the.relationship of the distance `scale 9tothediaphragm;'aperturevscale 7. When the ringf1301turns zinV a directionto-,open up the diaphragm laperture to a-.largeropening-(or a smaller fnumber on the scale `7)the bodily-movement of the plate 140will,:through therdriving-.pin` "-142, cause corresponding rotation ofthe'uring 116 `and,v through the-gears 122 and 1-24, opposite4rotationofzthe-ring 118, thus bringing the twopointer arms11 and 12closer to each other to indicate a reductionof-thezdepth of field, whichfollows from thexopening of the diaphragm to a larger aperture.Conversely, if .therings130 isy moved in a direction to closesdown`the'diaphragmaperture to a smaller stop (indicated by az-,larger fnumberon the scale 7) this will cause rotationof the rings 1116 :and 118 `in adirection to separate thev pointers `11 and 12 farther from each other,toindicate theincrease in the depth of lield which results from thesmaller diaphragm stop.

However, the motions of the rings 116 and 118` will not necessarily be-exactly the sameV in angular extent as the motion of the ring 130, butcan be varied by proper shaping of the ycam slot 148 to take care ,ofthe nonlinear relationship ,between variations '.ingdiaphragm aperture`size resulting from'movementof the 'rings 5 and 130, and variations, indepth of. focus `as expressed on the focusing scale or distance scale.9.'=`Thus when -the shape of the camslot .148 causes'the plate '140 toswing in one direction' or the other on its-zpivot 138, then in additionto the bodily movement of the plate 140A with its pivot, theswingingfmovement ofthe plate Y on this pivot will shift the position ofthetpin 1.42relative to the pivot 138 in a circumferential-.direction soas to cause a variation iup-the ,position of the'ring `116 relative tothe ring 13), so that the two lrings can be made to move in anon-linear` manner lrelative A-to teach other.

As will be readily seen from a study. ofthis` construction, theoperating gearing is, of a'` reversible nature, so that when either ofthe ,depth of eld indicating pointers is forcibly moved,A thiswillyfcausemovernent of the other one of the depth ofeld'indicatingpointers and also cause movement of the diaphragm apertureV adjusting orsettingy ring. Ofcourse Whenithezdiaphragm aperture adjusting or settingring isturnedg'athisjwill cause movement'of both of thezdepthof el'dindicating pointers.

In accordance with the present invention, and' as shown in Figures 1Aand 1B, either oneor-,both thepointers of the vdepth of field yindicatorare provided'with end pieces 11aV and/or v12a which are longitudinallydiskplaceable and which can be brought into ,engagement with 1the.focusing ring- 8 inone ofvseveral positions, in such a manner that it ispossiblewforthe` focusing ring to be entrainedwith-the depth of veldindicator or vice t VeI'S a.

The operation offan arrangementof )this kind will ample, the pointerk12. of the depth-of field indicator,

which indicates the more distant limit of satisfactory denition, hasbeen brought into engagement with a notch 13 in the focusing ring 8 atthe infinity point. As soon as the aperture setting 5 is rotated theresultant movement of the pointer 12of the depth of eld indicator willentrain the focusing ring 8. In other words, if the aperture is reducedand vthepointers of the depth of field indicator move further apart, thefocusing ring will be likewise turned in the direction of decreasingdistance,..the distant limit ofdefinition remaining at infinity in viewof the engagement of the pointer 12. There is lthereforean-assurance-that the --depthof -iieldv as de' terminedfby any settingof theV aperture of the stop will always be fully utilised and the lossin depth referred to in the introduction completely avoided.

The arrangement may likewise be used for the purpose of obtaining adesired .depth .ofield bysetting the focusing ring. Thedistantpointerll. remains locked at infinity whereas the Y-near pointer`11 is-set to the near limit of focus by rotating the focusing ring.Owing to the engagement of the pointer12..with the ring 9 any rotationofthe focusing ,ring .will at the same time actuate the stop mechanismthrough the'depth of field indicator 12 and its mechanism.

It is, of course, alsopossible to provide other positions at which thepointers ofthe depthjof lield indicator and thefocusing member can belocked. together. -For instancethe near pointer 11 might` be engaged atthe point which corresponds with .thedistance from the camera of aparticularobject, -such as a person it is desired to photograph, `andthe stop or focused distance adjusted to ensure that the entirefieldfromthe said object or person to infinity will have satisfactorydefinition. Alternatively, the distant pointer 12 may. be brought intoengagement at the point corresponding with the distance from the cameraof they object in question so that the entire depth of lieldl may be setto extend from a point between the camera and the said'object." Theresult of this would be for the background to be out of focus i.e.- ofbeing blurred. In Figure l' the camera is focused with reference to thefocusing scale, i.e..'adjusted to a distance which has been eitherestimated or measured by means of a separate range finder.

Clearly` the invention can belikewise applied to a camera provided witha coupled range finder. By locking the distant pointer atthe infinitypoint and focusing the camera to the desired'object, theaperture 'of thestop can be simultaneously and automatically set to a value which willjust extend the depth of the field to infinity, and theV loss of fielddepth hereinabove already referred to will not then occur. However, inthe case of a camera equipped with a coupled' range finder thealternative possibilities that have been described can beonlyinadequately performed because the plane of focus set by means oftherange' finder will 'always coincide with' the central index mark.However, Veven in a camera with automatic focusingthe'abovedescribedpossibilities/may be utilised if, according to -a further development ofthe invvention,-'the range'finder` andthe-focusing ring on the lens-canlikewise be coupled indifferent relative positions, andl-rnore'vparticularlw in such a way"that'the plane focused in the rangefinder will coincide either with the central index-markorrwith-thenear'orthe distant pointer of the depth-of-feldindicator.Such an'embodirnent is shown in Figure 2.v In principle, the camera iscon- -structed asY inthe previous example. #In other words, Ithereareagain providedlens lZZand a Lshutter 23 on the front-"of the camera bodyi21. -The shutter'specd Vand `^the-aperture of thestop are controlled bya speed ring 24A and an aperture setting ring 25. Unlike the arrangementillustrated'in Fig; 1 -t-hefocusing scale 'Z8 in the `present -instanceis fixed, focusing beingv performed by rotating -the -ring- 31inurelationl to the stationary scale. Inside the housing'of'thelensthe'setting ring 31 is connected in the conventional manner with a camwhich cooperates through intermediate elements with the range finder 33built into the camera body. In a camera of conventional constructionthis cam is rigidly coupled with the focusing ring so that the focusingscale will indicate the distance to which the camera has been focusedwith the aid of the range finder-for instance by two images in-the rangefinder having been brought to coincidence.

Unlike the known arrangement the embodiment of the invention illustratedin Figures 2 and 2a provides asecond ring 32 adapted for rotationrelatively to the setting ring 31, the cam being rigidly connected withthis second ring. The ring 32 is concentric with the ring 31 and can berotated in relation thereto. The ring 25 carries the gearing for theactuation of the pointers 43 and 44 of the depth of field indicator, sothat these pointers will move in relation to the fixed central indexmark 42 on the ring 31 according to the particular setting of the stopaperture, and thus indicate the depth of the field on the focusing scale28. The pointers 43 and 44 o-f the depth of field indicator and thecentral index mark 42 are so devised that the ring 32 which carries theactuating cam for the range finder can be coupled with one of the saidthree elements. This is diagrammatically illustrated in Figure 2a whichis a cross section on line A-A in Figure 2 on an enlarged scale. Thenear and distant pointers 43 and 44 of the depth of field indicator aresymmetrically moved towards or away from the central mark 42 through theabove mentioned gearing ywhich is actuated by the aperture settingmechanism. The undersides of the three pointers are provided withnotches 50. A catch 41 at the end of a spring 40 attached to the ring 32is adapted to engage the notch in either the central mark 42 or one ofthe two pointers 43, 44 of the depth of field indicator. The pointers 43and 44 are also adapted to be engaged with the teeth 45 in thestationary ring 46 which carries the focusing scale.

Let it be assumed, for instance, that the distant pointer 44 of thedepth of field indicator is coupled with ring 46 which carries thefocusing scale 28, at the infinity mark, `and that at the same time thepoint of focus of the range finder is coupled with the near pointer 43of the depth of field indicator by bringing spring 40 into engagementtherewith. When in such circumstances the camera is focused with the aidof the range nder it will be possible for instance to bring into focusan object or person in the foreground, but owing to the two pointers ofdepth of field indicator being coupled, on the one hand, with thefocusing ring and, on the other hand, with the range finder controlring, the stop aperture will be likewise varied through the depth offield indicator in such a manner that the depth of field will justextend from the object it is desired to photograph to infinity.

Other possibilities of utilizing this supplementary arrangement Will bereadily understood from the explanations that have already been givenwith reference to Figure 1.

It will be clear that a camera constructed according to the presentinvention will be particularly simple to manipulate if it includes acoupling between shutter and diaphragm, as described for instance inU.S. patent application, Ser. No. 389,779, filed November 2, 1953 (nowPatent 2,829,574, granted April 8, 1958). In this case, after a certainlexposure value has been setfor instance after consulting an exposuremeter-no further thought is required for setting an appropriate shutterspeed or stop aperture because with the help of the arrangement providedby the invention these factors are automatically set by suitablyselecting and positioning the limits of good definition within thepicture it is desired to take.

In the embodiments that have been described the member which carries thefocusing scale is provided with teeth with which at least one of thepointers of the depth of field indicator can be brought into engagement.However the application of the principle underlying the presentinvention would merely require that the member' carrying the focusingscale is provided with one or several stops which cooperate with atleast one of the pointers of the depth of field indicator and therebyrestrict the possible combinations of the settings of the focuseddistance and aperture of the stop. Figure 3 shows such a Simplified formof construction which corresponds with the general arrangement inFigure 1. In Figure 3 a stop 60 is provided only at the infinity pointof the scale. In other Words, the distance pointer of the depth of fieldindicator cannot be displaced beyond the infinity mark. The cameracannot therefore be focused beyond la distance at which the depth offield will just extend to in rinity and at which the distance pointer ofthe depth of field indicator will come into contact with the stop. Ifrequired, this stop may also be so arranged that it can be renderedineffective, by being movable out of the path of the pointer 12, asshown in Figure 3.

In the embodiments according to the Figs. l and 2 the member whichcarries the focusing scale is provided with a plurality of notches.However, the present invention might equally well be applied in cases inwhich said fousing scale member carries only one or a few notches atpreferred distance points. Fig. 4 shows such a simplified embodimentwhich corresponds with the general arrangement in Fig. l. In Fig. 4 thefocusing scale member 8 is provided with notches 70 and 72 only at theinitial and infinity points of the focusing scale 9,' one of thepointers 11a or 12a engaging one of said notches 7l) or 72,respectively. It will be readily understood, that the present embodimentoperates in the same manner as the arrangement according to Fig. l.

The above described examples all relate to ordinary photographiccameras. However, it will be readily understood that the invention isnot intended to be limited to this type of apparatus. The inventionmight equally Well be applied with advantage for instance to motionpicture cameras. In all such cases the main inventive idea resides inthe fact that at least one of the pointers of the depth of fieldindicator is connected cooperatively in a suitable manner thatcorresponding adjustment or joint setting of the focused distance andstop aperture is effected.

What is claimed is:

l. A photographic camera comprising a diaphragm aperture adjustingmember rotatable about an axis, a focusing distance scale, a pair ofdepth of field indicating members movable toward and away from eachother over said scale, means coupling said indicating members to eachother and to said aperture adjusting member to move both of saidindicating members from movement of said adjusting member and to movesaid adjusting member and one of said indicating members from movementof the other of said indicating members, and means for holding eitherone of said indicating members in any selected one of a plurality ofpredetermined positions relative to said scale.

2. A photographic camera comprising a diaphragm aperture adjustingmember rotatable about an axis, a focusing distance scale, a pair ofdepth of lield indicating members movable toward and away from eachother over said scale, means coupling said indicating members to eachother and to said aperture adjusting member to move both of saidindicating members from movement of said adjusting member and to movesaid adjusting member and one of said indicating members from movementof the other of said indicating members, a range finder control memberrotatable concentrically with said aperture adjusting member, andreleasable means for coupling said control member to one of saidindicating members to move said indicating members from movement of saidcontrol member and to move said control member from movement of saidindicating members.

3. A photographic camera comprising a diaphragm aperture adjustingmember rotatable about an axis, a

focusingdistancef'seale, a-pairtof depth of eld indicating membersmovable'towardand away from eachother over said scale," meanscouplingsaid indicating members toeach other and to, saidap'erture adjustingmember to move both of said indicating members from movement of saidadjusting ymemberand to move said adjusting member and one of saidVindicating members from movement'of `theother'of'said indicatingmembers,a range iinder control member rotatable 'concentrically With saidaperture `adjusting member, a range'flnder operating'ring mounted forrotation concentrically with said aperture adjustingmember andlsaidcontrol member, a'pointer earried by said'operating ring andsweepingacross"saidscale when said ring is turned, and releasable meansfor coupling said control member selectively either to said opervatingring to turnltherewith, o'r to one of said indicating .members to movetherewith.

l Reference'sited inthe le of this patent UNITED STATES PATENTS21,342,819 'z Priesemann Feb. 29, 1944 IA 2,350,009 'wBabcock et al May30, 1944 2,526,522 \-'Wallendorf Oct. '17,` 1950 v -FOREIGN PATENTS139,562 I Austria Nov. 26, 1934 1,111,448 `France Oct. 26, 1955,

